Load indicating device



Oct. 21, 1952 F. MILLER 2,614,420

LOAD INDICATING DEVICE Filed May 28, 1949 FRANK MILLER HIS ATTORNEY 4s 5 so 25 49 EB 32 C\ r. r I I I}: I l 45 4 l4 X I 25 a. '1: i -r- Z:

INVENTOR Patented a. 21, 1952 LOAD INDICATING DEVICE IiFrankMiller, Orange, N. J .,a ssign or to Ihgersbll- I v Rand Company,

of New J e'rsey' Application May 28, 1949, Serial No. 95,939 2 Claims. (Cl; ve -F1435 This invention relates to load indicating de- Vices and 'i'nore particularly to. load indicating devices for drill hoists.

- lon object of. this inventionis to indicate the torque onthe drum of a drillhoist.

. Another object of the invention is to control the rotation of the hoist drum. other objects will be evident from a study of the following specification.

In the drawings, in which similar reference numerals refer to similar parts,

Figure 1 is a side elevation showing a core drilling rig provided with the invention.

Fig. 2 is a side elevation, partly in section and. enlarged, showing the drill hoist and the load indicating device.

Fig. 3 is a sectional view of the bearing assembly taken on the lines 3-3 of Fig. 2.

In the practice of boring holes through rock formations, a cutter I9 is rotated by connected drill rod sections driven by a machine |2 at the top of the bore hole l3. This is called core drilling. For purposes of illustration a typical core drilling rig of the shot bit type is shown in Fig. 1 in which the cutter II] is composed of a core barrel l4 and a bit [5. Around the periphery of the bit l5 are diagonally located slots l6 containing steel shot IT. A derrick structure |9 over the hole |3 supports the drilling assembly which is raised and lowered by means of a wire rope 20. The rope is secured to a hoist 2| which receives and winds the rope 20 on a drum 22.

The abrasive action of the shot against the rock I9 does the cutting and because of this the weight, or load, on the bit must not be too great. If the load on the drill is too great, the bit will not bore a straight hole. It is the intention of the applicant to provide a load indicating device that will allow the hoist operator to know the load on the drill at all times thereby preventing any overload on the cutter. A preferred form of the invention is shown in detail in Fig. 2.

A hoist 2| having a drum 22 to receive the rope 29 and to hold the rope in tension is shown in the drawing. The drum 22 is provided with a brake 23 consisting of a brake band 24 which extends around the periphery of the drum 22 and which is secured to a brake lever 25 having opposed threads 26. By moving the lever 25 in one direction, the band 24 is tightened about the drum 22. If the brake lever 25 is moved in the opposite direction, the band 24 is loosened about the drum.

For the purpose of transmitting the torque on the drum to a loadindicating device,.a worm gear 2! is provided around the periphery ofjthe drum 22. A shaft 28, with its axis perpendicular to the axis of the drum 22, is provided with a.

worm 29 engaging the worm gear 21 on the drum 22 andconverting the rotary motion of the drum to linear motion ofthe shaft. Onev end of the shaft 23 terminates in a ratchet wheel 30.. A hand lever 3|, with a selective pawl 32 to enable the shaft 28 to ratchet in either direction, fits around the ratchet wheel 39 and allows the shaft 28 to control the rotation of the drum 22 when the brake 23 on the drum is released.

A measuring device 33 for measuring the torque on the drum 22 is provided on the end of the shaft 28 opposite the ratchet wheel 30. This device comprises a casing 34 having a cylindrical bore 35 into which the shaft 28 extends and is provided with a piston 39 attached to the end of the shaft 28. Fluid is adapted to fill that portion 31 of the cylinder 35 which lies between the piston 36 and the shaft end of the cylinder 38 and is introduced through a port 39. A pressure gauge 40 is attached to the casing 34 and indicates the fluid pressure.

While drilling the worm 29 on the shaft 28 is arranged to engage the worm gear 21 only when the cutter I0 is rotating. When pulling drill In from or returning it to the hole l3, the worm 29 is arranged to be disconnected from the gear 21 and to this end the shaft 29 and cylinder casing 34 are pivotally supported on a bracket 44. The casing 34 comprises a cylinder barrel 4| bolted to an end plate 42 which is pivotally connected to a vertical member 43 of the derrick structure I 9 by means of a bracket 44.

At its other end the shaft 28 is journaled on a post 45 having a, bearing assembly 46 to receive the shaft 28. The upper bearing half 41 is hinged to the lower half 48 in order that the shaft 28 may be inserted between them. When the shaft is in the bearing the worm 29 engages the worm gear 21. A hinged bolt 49 with a hand nut 50 fastens the bearing together. The top of the upper bearing 41 has a semi-circular depressionv worm gear 21 and worm 29 thence to the fluid in the cylinder 35 through the piston 36. The torque on the drum is indicated by the fluid pressure shown on the pressure gauge 40. The operator rotates the worm 29 by the hand lever 3| until the proper weight for the best drilling results is on the cutter l0. As long as the drill is in operation, the operator can maintain the proper pressure by referring to the pressure gauge 40 and by controlling the rotation of the drum 22 with the hand lever 3|.

While a specific form of the invention has been shown and described, it is to be understood that various changes and modifications may be made without departing from the spirit of the invention as set forth in the appended claims.

I claim:

1. In a load indicating device for drill hoists, a drum to receive a rope and to hold .the rope in tension, a worm gear around the periphery .of the drum,a shaft having a worm to engage der. having fluid therein enclosing the piston said cylinder having one of its ends pivoted to allow the worm on the piston shaft to be disengaged from the worm gear on the drum, and a measuring device for indicating the pressure on the fluid.

2. In a load indicating device for drum hoists,

4 a drum to receive a rope and to hold the rope in tension, a worm gear around the periphery of the drum, a shaft having a worm to engage the worm gear and to control the rotation of the drum, a piston on one end of the shaft, a cylinder enclosing the piston and having fluid therein, said cylinder having one of its ends pivoted to allow the worm on the piston shaft to be disengaged from-the worm gear on the drum, a pressure gauge communicating with the cylinder in order to indicate the pressure of the fluid in the cylinder, a clamp for holding the shaft against rotation in order to lock the drum, and manually operated means for efiecting rotationof .the shaft in order to adjust the load on thedrum.

FRANK MILLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Spalding Nov. 15, 1949 

